Diarrhoea, constipation, gastroenteritis Flashcards
Definition of diarrhoea
How is diarrhoea divided based on duration?
An increase in stool liquidity and/or increase in stool frequency.
<14 days = acute
>4 weeks = chronic
How is constipation commonly described?
When is constipation classed as chronic?
It is commonly described as incomplete emptying, excessive straining or reduced stool frequency (<3 times/week).
Constipation persisting >6weeks is termed chronic constipation.
Red flag symptoms for constipation
- Obstructive symptoms
- Weight loss
- PR bleeding
- Recent onset constipation
- Iron deficiency anaemia
- Age >50 without any previous cancer screening
Causes of acute diarrhoea
- Infective
- Gastroenteritis
- C. diff colitis
- Drug induced
- Antibiotics
- PPIs
- NSAIDs
- Digoxin
- Bloody
- Dysentry
- Acute flare of IBD
- Diverticulitis
- Ischaemic colitis
Classes of causes of chronic diarrhoea
- Functional (IBS)
- Inflammatory
- IBD
- Chronic mesenteric ischaemia
- Chronic infection
- Watery
- Fatty
Causes of watery diarrhoea
- Osmotic
- Dietry intolerance eg lactose, gluten
- Laxative overuse
- Secretory
- Bile acid malabsorption
- Microscopic colitis
- Hyperthyroidism, hypercalcaemia
- Colorectal cancer
Causes of fatty diarrhoea
Malabsorption disorders, eg SIBO, chronic pancreatitis, Whipple disease
Classes of causes of constipation
- Structural
- Normal transit
- Slow transit (motility disorder)
- Evacuation disorder
- Secondary constipation (including drugs)
Structural causes of constipation
- Diverticular disease
- Colorectal cancer
- Strictures (eg Crohn’s)
- Extrinsic compression, eg pelvic mass
Normal transit causes of constipation
- Irritable bowel syndrome
- Psychological - depression, anxiety associated constipation
Slow transit (motility disorder) causes of constipatation
- Post-op ileus
- Chronic intestinal pseudo-obstruction
- Hirschprung disease
- Neuromuscular disorders, eg MS, Parkinson disease, diabetic neuropathy
Evacuation disorder causes of constipation
- Ano-rectal conditions eg rectal prolapse, anal fissure
- Pelvic floor dysfunction
Causes of secondary constipation
- Low dietary fibre
- Inadequate hydration
- Immobility, old age
- Metabolic - hypothyroidism, hypercalcaemia, uraemia
- CKD
- Pregnancy
- Drugs
Medications which can cause constipation
- Opiates
- Anticholinergics eg TCA
- Calcium channel blockers
- Iron supplements
- Antidepressants
- Antacids
What is gastroenteritis?
Gastroenteritis is a non-specific term used to characterise symptoms of acute diarrhoea, nausea and vomiting and abdominal pain.